1. Field of the Invention
This invention relates to a side door hinge mechanism utilizing a quadric crank chain in a motor vehicle.
2. Description of the Prior Art
In most cases, the side door in a motor vehicle, such as a passenger car has heretofore been installed in a manner to be rotatable about a hinge affixed to a vehicle body for opening or closing of the door. In order to allow an occupant of the motor vehicle to open or close the side door for getting in or out of the motor vehicle, a door opening angle corresponding to the total length of the side door is required. Typically, when a space at the side of the motor vehicle is small, there are many cases where it is difficult for the occupant to get on or off the vehicle because the side door cannot be opened sufficiently.
To eliminate this difficulty, there has been proposed a side door hinge mechanism in a motor vehicle, as shown in U.S. Pat. Nos. 3,095,600 and 3,400,974, for example, wherein a quadric crank chain comprises a front rotary link disposed along the forward side of a vehicle body and connecting a side door to the vehicle body between rotary shafts disposed on the vehicle body and the side door, a rear rotary link disposed at the rear of the front rotary link, and connecting the side door and the vehicle body between rotary shafts, a portion extending along the vehicle body between the front and rear rotary links, and a portion extending along the side door between the front and rear rotary links.
In the side door hinge mechanism utilizing the above-described quadric crank chain, the rear rotary shaft for the rear rotary link is secured to an intermediate position along the longitudinal direction of an inner panel of the side door.
As a consequence, the rear rotary link protrudes into a compartment, interfering with a body or an arm of a driver or an occupant. There is also a risk that a finger may be pinched between the rear rotary link and the inner panel of the side door. Further the appearance of the interior of the compartment may be deteriorated.